1221303424 has 64 divisors (see below), whose sum is σ = 2660486400. Its totient is φ = 553835520.

The previous prime is 1221303401. The next prime is 1221303439. The reversal of 1221303424 is 4243031221.

It is a tau number, because it is divible by the number of its divisors (64).

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a junction number, because it is equal to n+sod(n) for n = 1221303395 and 1221303404.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 853942 + ... + 855370.

It is an arithmetic number, because the mean of its divisors is an integer number (41570100).

Almost surely, 2^1221303424 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221303424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1330243200).

1221303424 is an abundant number, since it is smaller than the sum of its proper divisors (1439182976).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1221303424 is a wasteful number, since it uses less digits than its factorization.

1221303424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2061 (or 2049 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 22.

The square root of 1221303424 is about 34947.1518725060. The cubic root of 1221303424 is about 1068.9101267594.

Adding to 1221303424 its reverse (4243031221), we get a palindrome (5464334645).

The spelling of 1221303424 in words is "one billion, two hundred twenty-one million, three hundred three thousand, four hundred twenty-four".